Sea Level Rise Past, Present, Future. Judith Curry Climate Forecast Applica0ons Network

Transcription

1 Sea Level Rise Past, Present, Future Judith Curry Climate Forecast Applica0ons Network

2 That s the big thing sea- level rise the planet could become ungovernable. Dr. James Hansen, former Director, NASA GISS We re talking about literally giving up on our coastal ci0es of the world and moving inland. Dr. Michael Mann, Penn State

3 Past and Projected Changes in Global Sea Level 6.6 O 4 O NOAA 1 O 0.66 O

4 Sea Level Rise Ques>ons Is the recent sea level rise unusual? What are the causes of sea level rise? How much sea level rise can we expect by 2050? What are the specific concerns regarding sea level rise in SE US? How will hurricanes and storm surges impact coastal ci0es?

5 Global sea level rise past 24,000 years XXXXXXXXXXXXXXXXXXXXXXXX

6 Paleo- reconstruc>on of global sea levels past 2500 years XXXXXXXXXXXXXXXXXXXXXXXX Xxxxx Kopp et al xxx Global sea level has varied ~ 10 inches over past 2500 years: sun, volcanoes, ocean oscilla0ons We can t tell whether current peak is greater than peaks AD

7 Recent global sea level rise acceleration started over 200 years ago Jevrejeva et al. 2008

8 Global sea level rise since 1900 Sea level rise since 1900: ~ 8 inches Increasing uncertainty prior to 1960 Substan0al sea level rise prior to 1950 No evidence of SLR accelera0on in recent decades Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Hay et al 2015

9 Is the IPCC s sea level rise conclusion justified? IPCC AR5 IPCC AR5: Since the early 1970 s, glacier mass loss and ocean thermal expansion from warming together explain about 75% of the observed global sea level rise (high confidence)

10 Global mean sea level rise (mm) El Nino El Nino La Nina Pinatubo ~3 inches since Recent research: trend ~ 2.7 mm/yr Satellite data set is too short and too uncertain to discern a significant accelera0on

11 Global varia>ons in sea level rise ( )

12 Sea level rise: coastal threat? Global avg sea level rise: 3 mm/yr Higher local levels of sea level rise can t be explained by warming. Confounding factors for local sea level rise: Geological sinking/rising Ground water withdrawal River engineering NOAA

13 Sinking in Houston Up to 10 O sinking since 1920 Groundwater withdrawal causes massive subsidence Increases flood risk Ruins the efficiency of city drainage systems

14 New Orleans Following Katrina, federal government build levees, flood walls and pumps to protect against hurricanes 2017 flooding: A large number of drainage pumps were out of service. Pumps must suck rainwater out of storm drains and canals and push into a nearby lake or other water body.

15 South Florida Recent accelera0ng sea level rise on the south U.S. Atlan0c coast has been caused by El Nino and the North Atlan0c Oscilla0on pakern Valle- Levenson et al.( 2017)

16 Miami: High Tide Event Credit: Dr. Jennifer Jurado

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18 Hurricane Irma s Storm Surge

19 Coastal urban flooding issues Popula0on growth and urban development in coastal regions, flood plains and marsh/swamps are a 0cking 0me bomb Concrete jungles leave no place for the water to go Inadequate municipal wastewater infrastructure is causing floodwaters to be filled with sewage waste Safe Drinking Water Act viola0ons are exacerbated during floods Drainage pumps will be inopera0ve with loss of electric power Solu>ons: Land use policy Beker infrastructure and engineering

20 Is global warming making hurricanes more dangerous?

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22 Are hurricanes made worse by climate change? ** * Source: Ryan Maue Global tropical cyclone ACE US landfalling hurricanes Source: Roger Pielke Jr

23 Source: Robert Rohde

24 Source: Phil Klotzbach

25 : 3 landfalls Cat 4/ : 14 landfalls Cat 4/5

26 Whither Sea Level Rise in the 21 st Century?

27 21 st century projec>ons of sea level rise JC concerns that these projec0ons are too high: Evidence that climate models are running too hot Neglect of mul0- decadal and longer ocean oscilla0ons Neglect of volcanic erup0ons and solar varia0ons

28 Probability of sea level rise scenarios for 2100

29 What is causing recent sea level rise? From Cheng et al. 2017

30 Varia>ons in Greenland glacier mass balance

31 Atlan>c Mul>decadal Oscilla>on (AMO) Warm AMO: Net mel0ng of Greenland Ac0ve Atlan0c hurricanes Greater SLR Next shio to cool phase? ~ ?

32 West Antarc>c Ice Sheet (WAIS)

33 West Antarc>c Ice Sheet collapse? WAIS could collapse rapidly (1-2 centuries) via dynamic instability Complete collapse would raise sea level by 10 feet Collapse is possible, but too uncertain to assign probability

34 10 ` of sea level rise...

35 JC s Sea Level Rise Predic>on: Global sea level rise: 3 to 8 inches Transi0on to cool phase of the Atlan0c Mul0decadal Oscilla0on: Sea level rise: Ø SE US no longer accelera0ng Ø accelera0on north of Cape Hakeras (including NYC, Boston) Atlan0c hurricanes : Ø Lower overall hurricane ac0vity Ø Fewer major hurricanes

36 Conclusions Local sea level rise is driven by many factors Assump0ons about sea level rise from future global warming may be of minor relevance to local sea level rise Financial and local mi0ga0on decisions about the future need to consider the en0re local context of sea level rise If we only look at the problem star3ng with just the climate signal, then it leads down a different path than if we look at components of sea level rise that are important to decision- makers. - Kathleen White, US Army Corps of Engineers

37 Climate Forecast Applica>ons Network (CFAN) Providing the intelligence you need to manage weather and climate risks CFAN s world- class research team translates the latest research and forecast innova0ons into products that tackle our clients most challenging weather and climate risks: Predic0ons from days to decades Extreme events: tropical cyclones, floods, droughts, heat/cold waves Sectors: energy, agriculture, financial, reinsurance www. cfanclimate.net curry.judith@cfanclimate.com (404)